73909779561 has 16 divisors (see below), whose sum is σ = 110230848000. Its totient is φ = 48942491184.

The previous prime is 73909779557. The next prime is 73909779599. The reversal of 73909779561 is 16597790937.

It is not a de Polignac number, because 73909779561 - 2² = 73909779557 is a prime.

It is a super-2 number, since 2×73909779561² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (73909779551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9181881 + ... + 9189926.

It is an arithmetic number, because the mean of its divisors is an integer number (6889428000).

Almost surely, 2^73909779561 is an apocalyptic number.

It is an amenable number.

73909779561 is a deficient number, since it is larger than the sum of its proper divisors (36321068439).

73909779561 is a wasteful number, since it uses less digits than its factorization.

73909779561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18371965 (or 18371959 counting only the distinct ones).

The product of its (nonzero) digits is 22504230, while the sum is 63.

The spelling of 73909779561 in words is "seventy-three billion, nine hundred nine million, seven hundred seventy-nine thousand, five hundred sixty-one".